package com.tkmybatis.MD5;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.binary.Hex;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.math.BigInteger;
import java.nio.MappedByteBuffer;
import java.nio.channels.FileChannel;
import java.security.MessageDigest;
import java.util.Random;

@Slf4j
public class MD5 {
	/*
	 * 涓嬮潰杩欎簺S11-S44瀹為檯涓婃槸涓�釜4*4鐨勭煩闃碉紝鍦ㄥ師濮嬬殑C瀹炵幇涓槸鐢�define 瀹炵幇鐨勶紝
	 * 杩欓噷鎶婂畠浠疄鐜版垚涓簊tatic final鏄〃绀轰簡鍙锛屽垏鑳藉湪鍚屼竴涓繘绋嬬┖闂村唴鐨勫涓�Instance闂村叡浜�
	 */
	static final int S11 = 7;
	static final int S12 = 12;
	static final int S13 = 17;
	static final int S14 = 22;

	static final int S21 = 5;
	static final int S22 = 9;
	static final int S23 = 14;
	static final int S24 = 20;

	static final int S31 = 4;
	static final int S32 = 11;
	static final int S33 = 16;
	static final int S34 = 23;

	static final int S41 = 6;
	static final int S42 = 10;
	static final int S43 = 15;
	static final int S44 = 21;

	static final byte[] PADDING = { -128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
			0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
			0 };
	/*
	 * 涓嬮潰鐨勪笁涓垚鍛樻槸MD5璁＄畻杩囩▼涓敤鍒扮殑3涓牳蹇冩暟鎹紝鍦ㄥ師濮嬬殑C瀹炵幇涓�琚畾涔夊埌MD5_CTX缁撴瀯涓�
	 * 
	 */
	private long[] state = new long[4]; // state (ABCD)
	private long[] count = new long[2]; // number of bits, modulo 2^64 (lsb
	// first)
	private byte[] buffer = new byte[64]; // input buffer

	/*
	 * digestHexStr鏄疢D5鐨勫敮涓�竴涓叕鍏辨垚鍛橈紝鏄渶鏂颁竴娆¤绠楃粨鏋滅殑 16杩涘埗ASCII琛ㄧず.
	 */
	public String digestHexStr;

	/*
	 * digest,鏄渶鏂颁竴娆¤绠楃粨鏋滅殑2杩涘埗鍐呴儴琛ㄧず锛岃〃绀�28bit鐨凪D5鍊�
	 */
	private byte[] digest = new byte[16];

	/*
	 * getMD5ofStr鏄被MD5鏈�富瑕佺殑鍏叡鏂规硶锛屽叆鍙ｅ弬鏁版槸浣犳兂瑕佽繘琛孧D5鍙樻崲鐨勫瓧绗︿覆
	 * 杩斿洖鐨勬槸鍙樻崲瀹岀殑缁撴灉锛岃繖涓粨鏋滄槸浠庡叕鍏辨垚鍛榙igestHexStr鍙栧緱鐨勶紟
	 */
	public String getMD5ofStr(byte[] inbuf, int length) {
		md5Init();
		md5Update(inbuf, length);
		md5Final();
		digestHexStr = "";
		for (int i = 0; i < 16; i++) {
			digestHexStr += byteHEX(digest[i]);
		}
		return digestHexStr;

	}

	public byte[] getMD5ofBytes(byte[] inbuf, int length) {
		md5Init();
		md5Update(inbuf, length);
		md5Final();
		return digest;
	}

	public String getMD5ofStr(String inbuf) {
		try {
			byte[] bytes = inbuf.getBytes("utf-8");
			return getMD5ofStr(bytes, bytes.length);
		} catch (Exception e) {
			md5Init();
			md5Update(inbuf.getBytes(), inbuf.length());
			md5Final();
			digestHexStr = "";
			for (int i = 0; i < 16; i++) {
				digestHexStr += byteHEX(digest[i]);
			}
			return digestHexStr;
		}
	}

	// 杩欐槸MD5杩欎釜绫荤殑鏍囧噯鏋勯�鍑芥暟锛孞avaBean瑕佹眰鏈変竴涓猵ublic鐨勫苟涓旀病鏈夊弬鏁扮殑鏋勯�鍑芥暟
	public MD5() {
		md5Init();

		return;
	}

	/* md5Init鏄竴涓垵濮嬪寲鍑芥暟锛屽垵濮嬪寲鏍稿績鍙橀噺锛岃鍏ユ爣鍑嗙殑骞绘暟 */
	private void md5Init() {
		count[0] = 0L;
		count[1] = 0L;
		// /* Load magic initialization constants.

		state[0] = 0x67452301L;
		state[1] = 0xefcdab89L;
		state[2] = 0x98badcfeL;
		state[3] = 0x10325476L;

		return;
	}

	/*
	 * F, G, H ,I 鏄�涓熀鏈殑MD5鍑芥暟锛屽湪鍘熷鐨凪D5鐨凜瀹炵幇涓紝鐢变簬瀹冧滑鏄�
	 * 绠�崟鐨勪綅杩愮畻锛屽彲鑳藉嚭浜庢晥鐜囩殑鑰冭檻鎶婂畠浠疄鐜版垚浜嗗畯锛屽湪java涓紝鎴戜滑鎶婂畠浠�
	 * 瀹炵幇鎴愪簡private鏂规硶锛屽悕瀛椾繚鎸佷簡鍘熸潵C涓殑銆�
	 */

	private long F(long x, long y, long z) {
		return (x & y) | ((~x) & z);

	}

	private long G(long x, long y, long z) {
		return (x & z) | (y & (~z));

	}

	private long H(long x, long y, long z) {
		return x ^ y ^ z;
	}

	private long I(long x, long y, long z) {
		return y ^ (x | (~z));
	}

	/*
	 * FF,GG,HH鍜孖I灏嗚皟鐢‵,G,H,I杩涜杩戜竴姝ュ彉鎹�FF, GG, HH, and II transformations for
	 * rounds 1, 2, 3, and 4. Rotation is separate from addition to prevent
	 * recomputation.
	 */

	private long FF(long a, long b, long c, long d, long x, long s, long ac) {
		a += F(b, c, d) + x + ac;
		a = ((int) a << s) | ((int) a >>> (32 - s));
		a += b;
		return a;
	}

	private long GG(long a, long b, long c, long d, long x, long s, long ac) {
		a += G(b, c, d) + x + ac;
		a = ((int) a << s) | ((int) a >>> (32 - s));
		a += b;
		return a;
	}

	private long HH(long a, long b, long c, long d, long x, long s, long ac) {
		a += H(b, c, d) + x + ac;
		a = ((int) a << s) | ((int) a >>> (32 - s));
		a += b;
		return a;
	}

	private long II(long a, long b, long c, long d, long x, long s, long ac) {
		a += I(b, c, d) + x + ac;
		a = ((int) a << s) | ((int) a >>> (32 - s));
		a += b;
		return a;
	}

	/*
	 * md5Update鏄疢D5鐨勪富璁＄畻杩囩▼锛宨nbuf鏄鍙樻崲鐨勫瓧鑺備覆锛宨nputlen鏄暱搴︼紝杩欎釜
	 * 鍑芥暟鐢眊etMD5ofStr璋冪敤锛岃皟鐢ㄤ箣鍓嶉渶瑕佽皟鐢╩d5init锛屽洜姝ゆ妸瀹冭璁℃垚private鐨�
	 */
	private void md5Update(byte[] inbuf, int inputLen) {

		int i, index, partLen;
		byte[] block = new byte[64];
		index = (int) (count[0] >>> 3) & 0x3F;
		// /* Update number of bits */
		if ((count[0] += (inputLen << 3)) < (inputLen << 3))
			count[1]++;
		count[1] += (inputLen >>> 29);

		partLen = 64 - index;

		// Transform as many times as possible.
		if (inputLen >= partLen) {
			md5Memcpy(buffer, inbuf, index, 0, partLen);
			md5Transform(buffer);

			for (i = partLen; i + 63 < inputLen; i += 64) {

				md5Memcpy(block, inbuf, 0, i, 64);
				md5Transform(block);
			}
			index = 0;

		} else

			i = 0;

		// /* Buffer remaining input */
		md5Memcpy(buffer, inbuf, index, i, inputLen - i);

	}

	/*
	 * md5Final鏁寸悊鍜屽～鍐欒緭鍑虹粨鏋�
	 */
	private void md5Final() {
		byte[] bits = new byte[8];
		int index, padLen;

		// /* Save number of bits */
		Encode(bits, count, 8);

		// /* Pad out to 56 mod 64.
		index = (int) (count[0] >>> 3) & 0x3f;
		padLen = (index < 56) ? (56 - index) : (120 - index);
		md5Update(PADDING, padLen);

		// /* Append length (before padding) */
		md5Update(bits, 8);

		// /* Store state in digest */
		Encode(digest, state, 16);
	}

	/*
	 * md5Memcpy鏄竴涓唴閮ㄤ娇鐢ㄧ殑byte鏁扮粍鐨勫潡鎷疯礉鍑芥暟锛屼粠input鐨刬npos寮�鎶妉en闀垮害鐨�
	 * 瀛楄妭鎷疯礉鍒皁utput鐨刼utpos浣嶇疆寮�
	 */

	private void md5Memcpy(byte[] output, byte[] input, int outpos, int inpos, int len) {
		int i;
		for (i = 0; i < len; i++)
			output[outpos + i] = input[inpos + i];
	}

	/*
	 * md5Transform鏄疢D5鏍稿績鍙樻崲绋嬪簭锛屾湁md5Update璋冪敤锛宐lock鏄垎鍧楃殑鍘熷瀛楄妭
	 */
	private void md5Transform(byte block[]) {
		long a = state[0], b = state[1], c = state[2], d = state[3];
		long[] x = new long[16];

		Decode(x, block, 64);

		/* Round 1 */
		a = FF(a, b, c, d, x[0], S11, 0xd76aa478L); /* 1 */
		d = FF(d, a, b, c, x[1], S12, 0xe8c7b756L); /* 2 */
		c = FF(c, d, a, b, x[2], S13, 0x242070dbL); /* 3 */
		b = FF(b, c, d, a, x[3], S14, 0xc1bdceeeL); /* 4 */
		a = FF(a, b, c, d, x[4], S11, 0xf57c0fafL); /* 5 */
		d = FF(d, a, b, c, x[5], S12, 0x4787c62aL); /* 6 */
		c = FF(c, d, a, b, x[6], S13, 0xa8304613L); /* 7 */
		b = FF(b, c, d, a, x[7], S14, 0xfd469501L); /* 8 */
		a = FF(a, b, c, d, x[8], S11, 0x698098d8L); /* 9 */
		d = FF(d, a, b, c, x[9], S12, 0x8b44f7afL); /* 10 */
		c = FF(c, d, a, b, x[10], S13, 0xffff5bb1L); /* 11 */
		b = FF(b, c, d, a, x[11], S14, 0x895cd7beL); /* 12 */
		a = FF(a, b, c, d, x[12], S11, 0x6b901122L); /* 13 */
		d = FF(d, a, b, c, x[13], S12, 0xfd987193L); /* 14 */
		c = FF(c, d, a, b, x[14], S13, 0xa679438eL); /* 15 */
		b = FF(b, c, d, a, x[15], S14, 0x49b40821L); /* 16 */

		/* Round 2 */
		a = GG(a, b, c, d, x[1], S21, 0xf61e2562L); /* 17 */
		d = GG(d, a, b, c, x[6], S22, 0xc040b340L); /* 18 */
		c = GG(c, d, a, b, x[11], S23, 0x265e5a51L); /* 19 */
		b = GG(b, c, d, a, x[0], S24, 0xe9b6c7aaL); /* 20 */
		a = GG(a, b, c, d, x[5], S21, 0xd62f105dL); /* 21 */
		d = GG(d, a, b, c, x[10], S22, 0x2441453L); /* 22 */
		c = GG(c, d, a, b, x[15], S23, 0xd8a1e681L); /* 23 */
		b = GG(b, c, d, a, x[4], S24, 0xe7d3fbc8L); /* 24 */
		a = GG(a, b, c, d, x[9], S21, 0x21e1cde6L); /* 25 */
		d = GG(d, a, b, c, x[14], S22, 0xc33707d6L); /* 26 */
		c = GG(c, d, a, b, x[3], S23, 0xf4d50d87L); /* 27 */
		b = GG(b, c, d, a, x[8], S24, 0x455a14edL); /* 28 */
		a = GG(a, b, c, d, x[13], S21, 0xa9e3e905L); /* 29 */
		d = GG(d, a, b, c, x[2], S22, 0xfcefa3f8L); /* 30 */
		c = GG(c, d, a, b, x[7], S23, 0x676f02d9L); /* 31 */
		b = GG(b, c, d, a, x[12], S24, 0x8d2a4c8aL); /* 32 */

		/* Round 3 */
		a = HH(a, b, c, d, x[5], S31, 0xfffa3942L); /* 33 */
		d = HH(d, a, b, c, x[8], S32, 0x8771f681L); /* 34 */
		c = HH(c, d, a, b, x[11], S33, 0x6d9d6122L); /* 35 */
		b = HH(b, c, d, a, x[14], S34, 0xfde5380cL); /* 36 */
		a = HH(a, b, c, d, x[1], S31, 0xa4beea44L); /* 37 */
		d = HH(d, a, b, c, x[4], S32, 0x4bdecfa9L); /* 38 */
		c = HH(c, d, a, b, x[7], S33, 0xf6bb4b60L); /* 39 */
		b = HH(b, c, d, a, x[10], S34, 0xbebfbc70L); /* 40 */
		a = HH(a, b, c, d, x[13], S31, 0x289b7ec6L); /* 41 */
		d = HH(d, a, b, c, x[0], S32, 0xeaa127faL); /* 42 */
		c = HH(c, d, a, b, x[3], S33, 0xd4ef3085L); /* 43 */
		b = HH(b, c, d, a, x[6], S34, 0x4881d05L); /* 44 */
		a = HH(a, b, c, d, x[9], S31, 0xd9d4d039L); /* 45 */
		d = HH(d, a, b, c, x[12], S32, 0xe6db99e5L); /* 46 */
		c = HH(c, d, a, b, x[15], S33, 0x1fa27cf8L); /* 47 */
		b = HH(b, c, d, a, x[2], S34, 0xc4ac5665L); /* 48 */

		/* Round 4 */
		a = II(a, b, c, d, x[0], S41, 0xf4292244L); /* 49 */
		d = II(d, a, b, c, x[7], S42, 0x432aff97L); /* 50 */
		c = II(c, d, a, b, x[14], S43, 0xab9423a7L); /* 51 */
		b = II(b, c, d, a, x[5], S44, 0xfc93a039L); /* 52 */
		a = II(a, b, c, d, x[12], S41, 0x655b59c3L); /* 53 */
		d = II(d, a, b, c, x[3], S42, 0x8f0ccc92L); /* 54 */
		c = II(c, d, a, b, x[10], S43, 0xffeff47dL); /* 55 */
		b = II(b, c, d, a, x[1], S44, 0x85845dd1L); /* 56 */
		a = II(a, b, c, d, x[8], S41, 0x6fa87e4fL); /* 57 */
		d = II(d, a, b, c, x[15], S42, 0xfe2ce6e0L); /* 58 */
		c = II(c, d, a, b, x[6], S43, 0xa3014314L); /* 59 */
		b = II(b, c, d, a, x[13], S44, 0x4e0811a1L); /* 60 */
		a = II(a, b, c, d, x[4], S41, 0xf7537e82L); /* 61 */
		d = II(d, a, b, c, x[11], S42, 0xbd3af235L); /* 62 */
		c = II(c, d, a, b, x[2], S43, 0x2ad7d2bbL); /* 63 */
		b = II(b, c, d, a, x[9], S44, 0xeb86d391L); /* 64 */

		state[0] += a;
		state[1] += b;
		state[2] += c;
		state[3] += d;

	}

	/*
	 * Encode鎶妉ong鏁扮粍鎸夐『搴忔媶鎴恇yte鏁扮粍锛屽洜涓簀ava鐨刲ong绫诲瀷鏄�4bit鐨勶紝
	 * 鍙媶浣�2bit锛屼互閫傚簲鍘熷C瀹炵幇鐨勭敤閫�
	 */
	private void Encode(byte[] output, long[] input, int len) {
		int i, j;
		for (i = 0, j = 0; j < len; i++, j += 4) {
			output[j] = (byte) (input[i] & 0xffL);
			output[j + 1] = (byte) ((input[i] >>> 8) & 0xffL);
			output[j + 2] = (byte) ((input[i] >>> 16) & 0xffL);
			output[j + 3] = (byte) ((input[i] >>> 24) & 0xffL);
		}
	}

	/*
	 * Decode鎶奲yte鏁扮粍鎸夐『搴忓悎鎴愭垚long鏁扮粍锛屽洜涓簀ava鐨刲ong绫诲瀷鏄�4bit鐨勶紝
	 * 鍙悎鎴愪綆32bit锛岄珮32bit娓呴浂锛屼互閫傚簲鍘熷C瀹炵幇鐨勭敤閫�
	 */
	private void Decode(long[] output, byte[] input, int len) {
		int i, j;
		for (i = 0, j = 0; j < len; i++, j += 4)
			output[i] = b2iu(input[j]) | (b2iu(input[j + 1]) << 8) | (b2iu(input[j + 2]) << 16)
					| (b2iu(input[j + 3]) << 24);

		return;
	}

	/*
	 * b2iu鏄垜鍐欑殑涓�釜鎶奲yte鎸夌収涓嶈�铏戞璐熷彿鐨勫師鍒欑殑锛傚崌浣嶏紓绋嬪簭锛屽洜涓簀ava娌℃湁unsigned杩愮畻
	 */
	public static long b2iu(byte b) {
		return b < 0 ? b & 0x7F + 128 : b;
	}

	/*
	 * byteHEX()锛岀敤鏉ユ妸涓�釜byte绫诲瀷鐨勬暟杞崲鎴愬崄鍏繘鍒剁殑ASCII琛ㄧず锛�
	 * 鍥犱负java涓殑byte鐨則oString鏃犳硶瀹炵幇杩欎竴鐐癸紝鎴戜滑鍙堟病鏈塁璇█涓殑 sprintf(outbuf,"%02X",ib)
	 */
	public static String byteHEX(byte ib) {
		char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
		char[] ob = new char[2];
		ob[0] = Digit[(ib >>> 4) & 0X0F];
		ob[1] = Digit[ib & 0X0F];
		String s = new String(ob);
		return s;
	}

	public static String getMd5ByFile(File file) throws FileNotFoundException {
		String value = null;
		FileInputStream in = new FileInputStream(file);
		try {
			MappedByteBuffer byteBuffer = in.getChannel().map(FileChannel.MapMode.READ_ONLY, 0, file.length());
			MessageDigest md5 = MessageDigest.getInstance("MD5");
			md5.update(byteBuffer);
			BigInteger bi = new BigInteger(1, md5.digest());
			value = bi.toString(16);
		} catch (Exception e) {
			log.error("error:",e);
		} finally {
			if (null != in) {
				try {
					in.close();
				} catch (IOException e) {
					log.error("error:",e);
				}
			}
		}
		return value;
	}

	// 生成“盐”和加盐后的MD5码，并将盐混入到MD5码中
	public static String generate() {
		// 生成一个16位的随机数，也就是所谓的“盐”
		Random r = new Random();
		StringBuilder sb = new StringBuilder(16);
		sb.append(r.nextInt(99999999)).append(r.nextInt(99999999));
		int len = sb.length();
		if (len < 16) {
			for (int i = 0; i < 16 - len; i++) {
				sb.append("0");
			}
		}
		String salt = sb.toString();
		return salt;
	}

	// 验证明文和加盐后的MD5码是否匹配
	public static boolean verify(String password, String md5) {
		// 先从MD5码中取出之前加的“盐”和加“盐”后生成的MD5码
		char[] cs1 = new char[32];
		char[] cs2 = new char[16];
		for (int i = 0; i < 48; i += 3) {
			cs1[i / 3 * 2] = md5.charAt(i);
			cs1[i / 3 * 2 + 1] = md5.charAt(i + 2);
			cs2[i / 3] = md5.charAt(i + 1);
		}
		String salt = new String(cs2);
		// 比较二者是否相同
		return md5Hex(password + salt).equals(new String(cs1));
	}
	
	public static String md5Hex(String password, String salt) {
		// 将“盐”加到明文中，并生成新的MD5码
		password = md5Hex(password + salt);
		// 将“盐”混到新生成的MD5码中，之所以这样做是为了后期更方便的校验明文和秘文，也可以不用这么做，不过要将“盐”单独存下来，不推荐这种方式
		char[] cs = new char[48];
		for (int i = 0; i < 48; i += 3) {
			cs[i] = password.charAt(i / 3 * 2);
			char c = salt.charAt(i / 3);
			cs[i + 1] = c;
			cs[i + 2] = password.charAt(i / 3 * 2 + 1);
		}
		return new String(cs);
	}

	// 生成MD5
	private static String md5Hex(String src) {
		try {
			MessageDigest md5 = MessageDigest.getInstance("MD5");
			byte[] bs = md5.digest(src.getBytes());
			return new String(new Hex().encode(bs));
		} catch (Exception e) {
			return null;
		}
	}
}
